Electro-hydraulic system for operating elevatable chairs



June 8, 1965 c. L. REDFIELD ETAL ELECTRO-HYDRAULIC SYSTEM FOR OPERATING ELEVATABLE CHAIRS Filed Aug. 27, 1962 6 Sheets-Sheet 1 J1me 1965 c. L. REDFIELD ETAL 3,188,136

ELECTRO-HYDRAULIC SYSTEM FOR OPERATING ELEVATABLE CHAIRS 6 Sheets-Sheet 2 Filed Aug. 27, 1962 INVENTORJ [far/es l. KedfiB/d J1me 19.65 c. L. REDFIELD ETAL 3,183,136

ELECTED-HYDRAULIC SYSTEM FOR OPERATING ELEVATABL E CHAIRS Filed Aug. 27, 1962 s sheets-sheet s If I j I N VEN TORS fluff: l. Rea fie d June 8, 1965 c. REDFIELD ETAL' 3,188,136

ELECTRO HYDRAULIC SYSTEM FOR OPERATING ELEVATABLE CHAIRS Filed Aug. 27, 1962 6 Sheets-Sheet 4 June 8, 1965 c. L. REDFJEL D rETAL 3, 8,

ELECTRO-HYDRAULIC SYSTEM FOR OPERATING ELEVATABLE GHATRS :6 :Shee oS-Sheet 6 Filed Aug. 27, 1962 TTORNEYS Cfzazzaaif? Jolzzz A. Qiozz N nN I tional detail View taken VIII of FIGURE 5; i I

electro hydraplic operation of thechair;

United States Patent ELECTRO-HYDRAULHI SYSTEM FGR OPERATING- ELEVATAELE EHAHQS Charles L. Redlield, Downers Grove, and John A. Dloahy,

The present invention relates toiinprovements in the operation of elevatable chairs such as barber chairs, dental and surgical chairs, and the like.

Electro-hydraulic automation of elevatable chairs such asbarber chairs and the like presents various problems among which may be mentioned the attainment of an adequate elevating range, assurance against unintentional swivelling, integrated raising and lowering of the chair back, and the provision of an operating structure which 'will fit within the practical limits of size and space dimensions available in this type of chair.

It is, accordingly, an important object of the present invention to provide a novel electro-hydraulically operated chair actuating system which adequately meets all of the foregoing and other problems in a rugged, trouble-free, efiicient unit. l

r Another object of the inventionis to provide a new and improved multi-stage lift device for elevatable chairs.

- A further object of the invention is to provide a new and improved electro-hydraulic multi-stage chair lifting piston and electrical system.-

Still another object of the invention is to provide a new and improved hydraulic chair lifting telescopic piston structure and chair back actuating system.

A yet further object of the invention is to provide improved multi-stage chair lifting hydraulic piston structure Other objects, features and advantages of the present invention will be-readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawing 7 wherein:

FIGURE 1 is a side elevational view of'a power operated chair embodying features of the present invention; FIGURE 2 is a side elevational view, partially in section, and partially broken away of the base and lifting cylinder mechanism of the chair;

FIGURE 3 is a sectional elevational'detail view taken- 'substantially on the line IIIIII of FIGURE I FIGURE 4 is a top plan view of the base and chair risingcylinder' assembly; a

FIGURE 5 is a fragmentary vertical sectional detail view taken substantially on the line V-'-V of FIGURE 3; FIGURE 6is afragm'entary vertical sectional detail FIGURE 10 is a schematic hydraulic circuit diagram also showing certain parts schematically, and

FIGURE 11 is a fragmentary, generally schematic side. elevational view of an elevatable chair substantially as in FIGURE 1, but on an enlarged scale and with certain parts omitted, to show how the backrest and footrest members are adapted to be actuated in coordinated relation.

A typical elevatable chair embodying the present invention is shown in FIGURES l and 11, in this instance comprising a barber chair, although the invention is equally applicable to dentist and surgical chairs. As shown, the chair comprises a base structure 15 to rest upon a floor surface and comprising a lower stabilizing housing 17, a cooperating upper housing portion 18 and an upstanding standard housing shroud 19. Supported above and upon the base 15 is a chair seat including frame structure 20, carrying a backrest 21, a footrest 22 and armrests 23, one of which is shown.

According to the present invention, support of the dead weight of the chair is directly upon the floor. To this end a seat plate 24 (FIG. 2) having bolt holes 25 (FIG. 4) to which the chair seat 2tI-is suitably bolted is carried at the upper end of a telescopic column 27 including a base block 28 bearing against the floor through a bottom plate 29 which closes the lower end of the shell-like stabilizer housing 17.

In order to enable raising and lowering of the chair throughout a substantial elevational range, the telescopic column or standard 27 comprises compound or plural telescopic structure as best visualized in FIGURES 2, 5

' and 7. To this end, rising from the base block 28 is a view taken substantially onlthe line VIVI of FIG- FIGURE 7 is an enlarged fragmentary horizontal sec- 1 I tional detail view taken substantially on the line VII VII of FIGURE 2;

FIGURE '8 is a fragmentary enlarged horizontal FIGURE 9 is awiring diagram showing certainparts schematically of the operating and control circuitry for sec' substantially-on the line VIIl central integral column portion 29 which rises to a limited height and fixedly supports within a stepped bore 30 thereof an upwardly projecting manifold tuoe assembly 31 including an outer tube 32, and an inner slightly smaller diameter tube 33, both of which have their lower ends fixed in fiuid tight relation in the column 29, while at their upper ends they support a fixed ring closure and bearing assembly 34. Thus, the manifold assembly 31 provides an upward stationary extension of the column 29 onthe base block 28.

Telescopically mounted about the manifold tube assembly' 31 is a compound cylinder 35 provided with a central hydraulic chamber 37 within which the manifold tube assembly 31 is received with a limited concentric spacing about the outer tube 32. On its lower end the cylinder 35 carries an annular retaining disk 38 retainingly clamping a sealing disk ring 39 and effecting sliding sealing engagement with the cylindrical wallof the manifold tube 32. Onits upper end, the cylinder 35 has fixed thereon a closure cap 40 of the same diameter as the the parts, the stop plug 41 will come to rest on the bearing 42.

Actual connection of the seat plate 24 with the telescopic'standard is through a plurality of piston rods 43 having threaded upper end portions securedf as, by nuts "44 to the seat-plate and extending downwardly through respective bores 45 into respective cylinder bores 47 in fluid sealing relation. In a desirable arrangement, three of the cylinders 43 and pistons 48 are provided, equidistantly ci-rcumferentially spaced as best seen in FIG. 7. Although for illustrative purposes, the seat plate 24 is shown as elevated above the closure disk member 40, in the fully collapsed telescoped relationship of the parts, the seat plate 34 can rest directly on the closure disk member 40. As a result, when the seat plate 24 rests on the closure disk head member 40, and the closure plug 41 rests upon the bearing assembly 42, there is direct dead Weight thrust support of the chair by the supporting column afforded by the manifold tube assembly 31, the column portion 29 and the base block 23.

Hydraulic means are provided for raising the chair through the compound ,multi-elevating action of the cylinder 35 and the pistons 48 wherein the cylinder 35 is :driven hydraulically to rise relative to the manifold tube assembly 31 and the pistons 48 are hydraulically driven to rise not only with the cylinder 35 but also relative to the cylinder 35. To this end, means are provided for introducing hydraulic fluid into the chair raising column through the base block 28 which is for this purpose provided with a delivery passage duct 49 (FIG. 4) leading to a riser duct passage 50 in the base column portion 29 which in turn communicates with a chamber 51 between the manifold tubes 32 and 33 having at the upper end of the manifold tube column a port 52 through the tube 32 by which the hydraulic fluid enters the hydraulic cylinder chamber 37 whereby to act upon the pressure receiving surface afforded by the closure plug portion 41 to raise the cylinder 35. From the hydraulic pressure chamber 37 the hydraulic pressure fiuid introduced thereinto in part bleeds through respective ports 53 into the lower ends of the hydraulic cylinders 47 under the pistons 48 and drives the same upwardly whereby through the piston rods 43 the seat plate 24 is driven upwardly relative to the cylinder 35. Lowering of the chair is effected by reverse-flow of the hydraulic fluid. As a result of this compound action of the cylinder 35 and the pistons 48, very rapid raising and lowering of the chair can be elfected with a smooth uniform action, while at the same time minutely incremental raising and lowering can be effected throughout the operative range of the raising and lowering device.

Another advantage of the compound telescopic raising arrangement resides in the multi-stage extension that is eltected from an unusually low collapsed condition of the raising and lowering assembly. This results from the telescoping of the cylinder 35 over the manifold tube assembly 31 throughout substantially the length of the cylinder, and the telescopic disposition of the piston rods 43.within the cylinder 35 throughout substantially the length of the piston rods in the fully collapsed condition of the device, and the substantially full length extension of the cylinder 35 relative to the manifold tube assembly 31 and the full length extension of the piston rods 43 relative to the cylinder 35 in the fully extended or protracted condition of the device. lift of from 14 inches in the lowermost collapsed or retracted condition of the device to a raised position of 28 inches from the floor inthe fully protracted condition of the device is attainable while maintaining full stability against tilting.

In order to avoid vibrations or noise due to incremental hydraulic fiuid pressurization in the cylinder chamber 37, a pocket of air is preferably provided in the upper end thereof within the lift cylinder 35 over the 4 under full load. This is accomplished by the present invention without any strain, torque or twisting on the piston rods .3 or any other operating mechanism extending between the elevating device and the seat plate 24. To this end, means are provided which not only enable entirely free vertical raising and lowering adjustments to be made throughout the entire substantial range of the present device, but also enable complete freedom for unlimited turning of the chair about the axis of the raising and lowering device, with all torque stresses completely isolated from the raising and lowering mechanism. To the accomplishment of this end, a multiangular sided torque tube 54 is secured rigidly at its upper end to the underside of the seat plate 24 in any suitable manner as by welding, brazing or by screws 55 (FIGS. 3, 4 and 5) and depends in free telescoping relation about the operating cylinder assembly to a length where the lower end of the torque tube in the fully collapsed, lowered condition of the assembly is adjacent to the base block 28. g

Means are provided for retaining the torque tube 54 in any preferred torsional orientation while in such orientation enabling free raising and lowering movement of the chair throughout at least the major extent of the elevaticnal range of the device. Accordingly, a rotation lock tube 57 is provided which is of an inside diameter large enough to accommodate the angularly cross-sectioned torque tube 54 and bearing assemblies 58 connecting the tubes corotationally but relatively axially telescopically movably. In length the rotation lock tube 57 is sufficient to serve its rotation lock function and also to extend downwardly about the torque tube 54 and other mechanism on the lower portion of the telescoping mechanism column as In practice, a seat plate top of the manifold tube assembly 31 and substantially above the port 52 which is located substantiallybelow the top of the manifold tube assembly. Such air pocket effectively damps any tendency toward vibrational ham mering by incremental introduction of pressurized hydraulic fluid.

Barber and like chairs must, in addition to raising and lowering capability, be possessed of the ability to swivel a protective skirt as best visualized in FIG. 2.

Externally the rotation'lock tube 57 is smoothly cylindrical and it is supported by a rigid tubular brake housing column member 59 having on its lower end a rigid lateral attachment flange 66 secured in suitable manner by means such as screws 61 to the housing member 18 and more particularly to a margin in the top of the housing shell member 18 about a complementary opening 62 therein within which the lower end portion of the brake housing tube 59 is accommodated. Turning of the brake housing member 59 relative to the base housing member 18 is thereby precluded, and turning of the base housing memher 18 relative to the bottom base housing 17 is precluded by virtue of nesting of an asymmetric lower marginal portion of the base housing member 18 Within a complementary recess 62a in the lower base member 17 which, in turn, spreads to a substantial diameter in order toatford maximum stability against tilting of the chair unit. This arrangement also affords with the base plate 29 ample frictional contact with the floor to substantially preclude turning of the base 15 under normal torque encountered in the turning of the chair in service, and more particularly during braking of turning movements.

In a desirable form, the tubular brake housing 55 is constructed in two semi-cylindrical portions (FIG. 7) secured together to an inside diameter slightly larger than the opposing outside diameter of the rotation lock tube 57 as by means of screws 63 extending across the opposing vertical joint edges of the brake housing segments. This enables drawing up the brake housing segments about the rotation lock tube 57 to effect optimum slidable engagement pressure of generally semi-cylindrical or split bearing ring segments 64 mounted in suitable grooves 65 in the inner walls .of the brake housing segments adjacent to the top'end of the housing and corresponding bearing segments 67 mounted in grooves 68 in the inside face or wall of the housing segments adjacent to its lower end. The bearing segments 64 and 67 project slightly inwardly from the inner housing segments to a diameter substan tially equal to the opposing outside diameter of the rota-- tion lock tube 57 and firmly slidably engage such outside" diameter, the proper sliding tensionedgrip or engagement being effected by means of the screws 63, not only to equalize the gripping engagement of the bearings but also to effect take-up after the bearings have been worn in.

By preference, the bearings 64 and 68 are constructed of a material which will not require lubrication and which need not be made with critical tolerances. A highly desirablematerial for this purpose comprises a steel backing filled with a mixture of lead, bronze and a plastic such as polytetrafluoroethylene. The plastic is available under the tradename Teflon.

By having the bearings 64 and 68 made from a material that does not require lubrication is advantageous not only to avoid the necessity for lubricating the bearings and more particularly the engaged cylindrical surface of the tube 5'7, but also by maintaining the outer perimeter of the tube 57 substantially free from lubricant facilitating the braking grip of a brake band 69 on such perimeter. A circumferential groove 70 in the inside diameter wall of the brake housing 59 freely clears the brake band 69 while a slot 71 at one side of the brake housing affords access of one end of the brake to an anchor 72, while the opposite end of the brake band 69 is secured to a brake actuating mechanism 73 (FIGS. 2, 3 and 4).

In a desirable form, the brake actuating mechanism 73 comprises a toggle linkage arrangement including a lever arm 74 attached adjacent to one of its ends as by means of a bolt 75 to the appropriate end portion of the brake band 69, and with the attached end of the lever projecting in the same direction as the end of the band to which attached. This connection through the connecting bolt '75 is pivotal so that the lever '74 can be rocked about the axis of the connecting :bolt. from the connection 75 along the length of the lever 74 a pivotal connection as by means of a bolt 77 is effected with one end portion of .a toggle link 78 which has its opposite end portion pivotally connected as by means of a bolt 79 to the bridge portion of a generally U-shaped bracket 80 rigidly secured to the brake housing 59. The lever '74 projects to a substantial extent beyond the bracket 80 and has its remaining end portion pivotally connected 1 to thrust links 81 carried on a piston rod 82 of a piston (not shown) in a hydraulic brake cylinder 33 mounted on the brake'housing flange 60 substantially as shown.

I, Normally the toggle lever 74 is drawn into brake set- Spaced a limited distance respective faces of the torque tube 54 (FIG. 7).

portion of a plunger rod 87 projecting upwardly through the flange 60 and having connecting links 88 thereon coupled pivotally to the lever 74 between the bracket 8t? and the brake cylinder yoke 81. In this relationship the toggle linkage, being fully extended pulls the brake band 69 tightly into braking compression against the rotation lock I tube 57 which thereby through the connecting bearing structure 58 holds the torque tube 54 against turning and thus also the ehairseat frame structure 24 and the chair. a When .it is desired to release the brake for turning the chair, the brake cylinder 83 is activated to drive the piston rod 82 and thereby the links 81 upwardly to rock the toggle lever 74-, whereupon thetoggle link 78 acts to draw can be turned as' desired until the toggle lever. 74 is returned by'the brake'js'pring 841d brake setting position;

Although when the brake is released the chair can be turned with some freedom, the bearings 64 and 67'maintain some frictionalcontrol upon the rotation lock tube 57,

as by means of screws 91 to and extending between the land portions 90 of the two rings are respective vertical tie plates 92 of athickness relative to the spacing between the land portions 94) and the opposing fiat faces of the tube 54 to afford suiiicient space to accommodate respective upper and lower bearing strips 93 secured to the inner faces of the tie plates as by means of screws 94. The bearing strips are preferably made from the same material as the segmental bearing strips 64 and 67 previously described so that they can function in slidable engagement with the respective faces of the tube 54 Without requiring lubrication. In other words, the bearing strips 93 are of a self-lubricated material. For efficient functioning, the bearing strips 93 should engage the faces of the torque tube 54 reasonably snugly though slidably. Two assure this coacti-on, certain of the tie plates 92 are adjustably mounted as shown, for example, at the left and lower sides in FIGURE 7, that is in the square arrangement shown, two of the tie plates in 90. adjacency. For this purpose, respective sets of set screws 95 are carried by the land portions 90 of the rings 89 thrusting against the back faces of the tie plates 92 whereby to effect proper sliding bearing engagement of the associated bearing strips 93 against the rotation lock tube 54. Properly adjusted relationship is maintained by the associated attachment screws 91, serving thus to lock the respective adjustable tie plates 92 in adjustment. As a result of this arrangement, not only is adjustment of bearing pressure effected in respect to the adjustable tie plates 92, but also in respect to the directly opposite stationary tie plates 92, so that substantially equalized bearing grip is attained on all faces of the (in this instance) square rotation lock tube 54 maintaining it firmly corotational with the round rotation lock tube 57. Nevertheless, the angular cross-section tube 54 is readily movable vertically during height adjustments of the chair.

Since in order to attain full upper limit height adjustment in excess of the length of the inner rotation lock square tube, 54, there must be not only relative telescoping of the torque tube 54 of the rotation lock assembly relative to'the rotation lock tube 57, but also telescoping capability of the tube 57 relative to the brake housing tube structure 59, means are provided for locking the tubes 54 and 57 through the bearing structure 58 when the inner torque tube 54- has attained maximum permissible elevationaldisposition as dictated by relative length considerations with respect tothe rotation lock tube 57.

as determined by tightening of the take-up screws 63 to Y Y avoid undue swivelli g freedomo'f'thechair, thusjenabling I convenient but reasonjablyand desirably controlledturnf ingofthe :hair. w

v desirable construction of the'bearing assembly Conveniently, such interlock means compriserespectivelength to provide for the second stage of extension of the rotation lock tube assembly'following first-stage extension or protraction by the torque tube 54. During return or lowering or retraction as required =bythe lowering of the, chair, snugness of the bearing engagement of the torque tube 54 may cause the entire rotation lock tube "assembly to move downwardly as a unit until the lower end portion of the rotation lock tube 57 engages'a stop surface 28a (FIGURE 2) on thebase of the chair elevating unit whereafter the torque tube 54' continues "downward telescoping movement relative tojthe tube 57 un-til the lowest limit of the chairis reached.

In order to-' avoid entrance of foreign matter such as hair clippings and-the likeb'etween the rotation lock .tube 57 and;.--thejbrakehousing'59, a circular seal including Secured means such as a felt or other wiper type sealing ring 98 is mounted on the upper end of the brake housing to engage the outer diameter of the tube 57. Suitable compressible gasket strip 99 is engaged in the joints between the brake housing segments .(FIG. 7) for this same purpose. Similarly, foreign material is excluded from entering between the tubes 54 and 57 by suitable sealing ring means including a flexible lip 100 mounted on the upper end of the uppermost of the rings 89 and overlying the tie plates 92 and bearings 93 and sealingly slidably engaging the outer angular perimeter of the torque tube 54 (FIG. 2

Fully powered, semiautomatic operation of the chair is facilitated by convenient location thereon, as for example on one of the arm rests 23, of an electrical control and power outlet panel 101. This, of course, creates some problems in electrically connecting various electrically motivated control devices with the control panel 101, in view of the desirability for unlimited swivelling or turning of the chair and without any restrictions from electrical leads or other connections.

According to the present invention, desirable means for eifecting the electrical connections comprise a rotary conductor assembly 1112 (FIGS. 2, 5 and 6) by which electrical connection between stationary leads 103 in the base portion of the device and conducting means in the relatively rotary portion of the device is effected. For this purpose, the central column portion 29 of the base block 28 has fixedly mounted thereon a cylindrical sleeve 104 provided adjacent to its lower end with an upwardly facing shoulder 105 on which is rotatably seated a stack of substantially rigid insulating disks 1117 of polygonal outline substantially complementary to the inside polygonal shape of the torque tube 54 but slightly smaller to be received freely therein and provided with respective upstanding integral spacer flanges 1118 maintaining the disks separated to provide respective spaces therebetween to accommodate electrically conductive slip rings 169 (FIGS. 5 and 8) encircling the sleeve 1114. Each of the rings 109 has a tang 110 which projects radially inwardly into a respective vertical lead clearance vertical groove 111 opening radially outwardly in the sleeve 11M. Thereby not only is each of the slip rings 109 held stationary with respect to the sleeve 1114, but one of the leads 103 is attachable to the slip ring in electrically conductive connection as by means of a crimped-n flange 112 depending from the tang 110. Permanence in such connection can, of course, be assured by suitable soldering.

Each of the slip rings 109 presents a radially outer circular contact surface against which a spring cont-act arm 113 of complementary curved shape slidably en gages in electrical contacting relation. Intermediately the contact brush spring member has an engagement yoke 1-14 engaged about a brush post 11 whereby to retain the brush member .in fixed corotative relation with the rotatable insulating stack of the assembly. A divergent contact arm 1 17 of the brush has a contact terminal pad 118 to effect sliding electrical contact with a vertical contact strip 119 against which the pad presses by virtue of a spring loaded or biased relationship of the contact legs or arms 113 and 1 17. There are as many of the slip rings 169, spring brushes and vertical contact strips 119 in the assembly as there are electrical control circuits or branches in the chair operating circuitry, in this instance eight, as well illustrated in FEGURE 8.

Not only do the strips 119 serve as electrical conductors, but they also function as connectors tor retaining the stack of insulating rings members 107 assembled in proper alignment. For this purpose, the conductor strips 119 extend vertically through the 'margins of the disk rings 107 at the inner sides of the spaced flanges 8 as best seen in FIGURES Sand 8. At their lower ends, the conductor strips 119 have angular retaining flanges 120 engaging under the lowermost of the insu- Q o lator disks 187. On its upper end the stack of insulating disks and slip rings as well as spring brushes is retained against upward displacement from the fixedmsulator bushing or sleeve r104 by means of a reta ner disk ring 121 having an inner mar-gin retained within a groove 122 provided therefor in the upper end portion of the sleeve 164.

In order to provide for full electrical connection throughout the range of protraction of the telescopic chair elevating unit, the conductor strips .1 19 extend to a substantial height as best shown in FIG. 6 within the walls of an intermediate insulating tube 123 which firmly supports the conductor strips inside the torque tube 54 (FIG. 7) with respect to which the outer perimeter of the insulating tube is substantially complementary in slightly spaced relation to permit free telescoping movement of the torque tube 54 with the seat plate 24 relative to the insulator tube 123 which while it is corotative with the telescopic chair elevating mechanism, remains in a fixed elevation with the electrical assembly 1112 and the base member 28. Each of the conductor strips 119 is engaged within a vertical groove 124 provided therefor in the inner wall of the insulator tube 123, with opposed vertical retaining flanges 125 provided at the respective opposite sides of the groove and retainingiy overlapping the vertical margins of the strip 119 in a manner to leave the major inner face portion of the strip fully exposed. At their upper ends the conductor strips 119 project slightly above the insulator tube 123 and have turned over retaining terminal flanges 1 26 serving to retain the insulator tube 123 against axial sepa ration from the electrical transmission assembly 102. Electrical contact sliding engagement with the inner face portion of each of the conductor strips 119 is effected by n a lower terminal contact pad portion 127 of an opposed companion contact strip 128 mounted vertically on a face of a vertical insulator bar 129 secured as by means of screws 131) to the outer perimeter of the cylinder 35 Within a reentrant corner clearance space 131 afiorded within the insulator tube 123 as best visualized in FIG- URE 7. Attachment of the conductor strips 128 to the in each instance may be located about coextensive with.

the lower end of the insulator bar, the upper extremity of the conductor strip 128 projects upwardly above the insulator bar and is provided with an inwardly biased sliding contact finger or pad 132 engageable in electrically contacting relation with a respective conductor rod 133 slidably guided in a complementary vertical bore 134 in the associated insulator bar 129 and extending upwardly therefrom through a suitable bore 134 in the seat plate 24 of ample diameter to accommodate a preferably resilient insulating spacer bushing 135. On its upper end portion the conductor rod 1331s threaded, and upper and lower lock nuts 137 provided with internal insulating thread lock bushings 138 secure the rod fixedly to the seat plate, with an upper terminal end portion of the rod projecting sufficiently above the upper of the lock-nuts to enable attachment thereto of an electrical lead contact. Through this arrangement, a three stage telescoping, sliding electrical conductor assembly is effected for each electrical circuit or branch between the seat and the base, fully integrated for the full range of telescopic movement of the seat raising mechanism. i

It will thus be apparent, that by virtue of the rotary conductor assembly 1112 and its accessories as described, full push button control of the chair is adapted to be attained wherein raising and lowering, lockingand unlocking condition.

(locking, as well as reclining and return movement of the chair back can be controlled from the control panel 191 on the chair arm and nevertheless the chair can be rotated in unlimited manner about its axis. Schematically the electric circuitry including the rotary conductor assembly 192, for accomplishingtthis is depicted in FIG- URE 9, while the hydraulic circuitry controlled by the electrical circuitry isjschematically depicted in' FIG- ,URE 10.

Electrical power for the chair is brought through the base structure of the chair by electrical lead wires 139 connected through two of the slip rings .109 with the chair and tapped by an electrical receptacle 14%) mounted on the panel 101 (FIG. 1) to afford convenient outlet for electric clippers, shavers and the like. Also mounted on the panelltll in a convenient order is a push button 141 to effect raising of the chair and a push button 142 to effect lowering of the chair. Both of these push buttons are actuators for a normallyopen switch assembly 143. Also mounted onthe panel 1651 is a brake lock button 144 and a brake unlock button 145 for operating a two-way switch 147. H a

.If' it is desired to raise the chair the up orlift button 141 is pressed. This completesa circuit through a lead 148 through a relay 149 and a motor lead 150 to actuate a. pump motor 151 which drives a pump 152, both of which are located in a reservoir or sump 153 for hydraulic fluid such as oil (FIGURES 2, 4 and 10) located in the base 15 of themachine Hydraulicffiuid is thereby driven into a manifold 154 cored or drilled in the base block 28 (FIGS. 4, and At the same time a circuit through a lead 155 is energized to actuate a solenoid valve 157 for delivery of pressure fluid from the manifold 154 through a check valve 158 to the hydraulic'fluid passage or duct 50 (FIGS. 5 and 10) for effecting elevation of the chair by raising the cylinder 35 and the piston rod '43 while the lift button 141 remains pressed. Also at this .sump153. Thereby, should the brake be set or on when a demand to raise the chair is made by pressing the button 141, the brake is released to avoid any interference with raising of the chair throughout its full range. mediately upon release of the lift button 141, and assuming no other pressure demands have been effected by pressing I of an appropriate button, the pump motor 151'stops, the

solenoid valve 157 closes, the solenoid valve 159 closes, and the solenoid valve 162 opens. The check valve 158 holds the pressure fluid against return from the cylinder:

manifold so that'the chair remains at the desired elevation, and the brake cylinder 83 is evacuated byreturn of the which completes a circuit through lead 168 with the solenoid valve 162 opening such valve and releasing the hydraulic fluid from thebrake cylinder 83 whereby the brake spring 84 locks the brake. To open the brake, the brake release button is pressed whereby. through a lead 169 connecting with the relay 149, the motor 151 is energized and at the same time the solenoid valve 159 is opened and the solenoid valve 162is closed whereby hydraulic fluid is pumped to the brake cylinder 83 to unlock the brake. Immediately upon locking of the brake, a limit switch 170 in the lead 169 opens the circuit, stopping the pump motor 151, closing the solenoid'valve 159, the solenoid valve 162 remaining closed, and the brake cylinder 83 holding the brake in the unlocked position.

Means for effecting actuation of the backrest 21 and the footrest 22 electro-hydraulically are organized to operate by push button control through the chair supporting column including the manifold assembly 31 and the rotary electrical contact assembly 102. It will be seen in FIGURE 11 that the chair back and footrest are pivotally mounted on theframe structure-of the seat 20 and are connected by a linkage comprising a parallel bar construction P so that they operate together in known manner. For such an arrangement, an actuating cylinder 171 is suitably mounted at one end on the chair seat 20 and has its piston rod connected with the backrest,as shown, with a spring 172 normally loading the cylinder toward the normal or upright position of the backrest. Recline movement of the backrest is controlled by a push button 173 (FIG. 1), and return movement is controlled by a push button 174, both on the control panel 101 and arranged to actuate a normally open switch assembly 175 (FIG. 9).

When it is desired to effect reclining movement of the backrest, the button 173 is pushed which actuates the switch 175 which completes a circuit through a lead 177 with the lead 148 whereby to energize the pump motor 151. At the same time, a solenoid valve 178 in a conduit 179 '(FIG. 10) is opened for-delivery of hydraulic fluid through a check valve 136 to the recline cylinder 171 to effect reclining movement of the backrest in opposition fluid therefrom through the solenoid valve 162 to the 'rei turn manifold 164 and the brakereturns to the rotation When it is desired to lowerthe chair, the down button 142 is pressed, a solenoid valve 165 in a return duct 167 is opened to effect return communication'between the cylinder piston chamber 51 andthe return manifold 164 to return the hydraulic-fluid to the sump. If the rotation lock is on, the pump motor 151 is also actuated, the

solenoid valve 11- 59 opens and the solenoid valve :162 closes range lowering of the chair; Immediately upon releasing the down button142, the solenoid valves 165- and 159 to the biasing spring 172.

During recline actuation hydraulic fluid demand, the pump pressurized fluid is lead from the manifold 154 through a branch duct 181 (FIGS. 5 and 10) to the lower end of a chamber 182 provided interiorly of the manifold tube 33 which is fitted into the lower reduced diameter end portion of the bore 30 in the standard portion 29 of the base block. 'From the vertical chamber 182, the pressure fluid passes up through a manifold tube 183 which fits telescopically freely within the tube 33, is sealingly slidably engaged by the closure assembly 34 and is fixedly secured at its upper end centrally within the cap boss 41. From the upper end of the chamber provided within'the tube 185, the pressure fluid passes through a duct 184 cored or bored inthe cap 40 which communicafes with a; port 155m the lower face of the flange of the cap with an upwardly opening blind end bore 187. of Y 601 suitable length and diameter to clear telescopically a vertical duct tube 188 depending thereinto and projecting upwardly througha fluid seal 189 secured in the upper plate 24 where the upper end of the bore in the tube188- communicates with a passage 190 in turn communicating withthe duct 179 leading into the backrest actuating to unlock the rotation lock to avoid interference with full 1 '70 close, the pump motor 151 is deener'gized -and thesole- 'noid valve 162 opens, thereb y resetting'the brake; it I v Should it bedesired to. operate the brake independently offany other action 'ofthef chair, for example, to. lock 7 i the rotation lock, the brake. lock butto n 1'44- isipressed 75 cylinder 171. Through this arrangement, chair raising 'and lowering telescoping action of the device. are adequately accommodated while maintaining uninterrupted communication for delivery of pressure fluidfrom the manifold 154 to the duct 179. r,

In order to avoid locking the hydraulic system between sneaiae pressure relief passage duct 191 leads from the passage system including the delivery duct 181 and communicates through a solenoid valve 192 with the return duct 164. Thereby, the solenoid valve 192 normally blocks return flow of the hydraulic fluid and thus avoids any dissipation of pressurized fluid from the delivery duct 1-81 while the pump 152 is in operation. However, when the down button 142 is pressed for lowering the chair, it also, through an electrical lead 193 energizes the solenoid of the solenoid valve 19-2 to open the valve for return of the hydraulic fluid from the delivery side of the chair back actuating hydraulic system simultaneously and in parallel with return of hydraulic fluid through the return duct 167 through the solenoid valve 165.

Return of the backrest 21 of the chair is effected when the return button 174 is pressed by energizing and opening a solenoid valve assembly 194 in a return duct leading from the pressurized end of the cylinder 171 so that the hydraulic fluid is driven from the cylinder under the bias of the return spring 172. To accommodate such return flow, the telescopic manifold tube and cylinder assembly of the chair raising device affords suitable means including, as best seen in FIGURE 5, in the seat plate 24 a port or passage 197 which communicates with the upper end of a tube 198 fixedly secured in fluid tight relation within the underside of the seat plate and depending therefrom telescopically into the cylinder 35 in a counterpart relationship and structure to the tube 188 in the hydraulic fluid delivery system for the seat back actuating device. For this purpose the return system tube 198 extends telescopically into a clearance bore 199 (FIG. 7) in the cylinder 35 into which it discharges, and which bore communicates through a passage 20% (FIG. in the cap 40 into the upper end of a telescopic'small diameter return flow tube 201 having its upper end secured centrally in the cap as and extending down through a sealing closure 2H2 at the upper end of an upstanding manifold tube 203 of slightly smaller outside diameter than and inside the depending manifold tube 183. At its lower end the manifold tube 293 is secured centnally in the lower end portion of the base column 29 and communicates with a return passage 284 in the base 28 from which a return line duct 2&5 (FIG. leads freely to the sump 153. As a result, there is, in effect, free dumping of hydraulic fluid from the cylinder 171 when the solenoid valve 194 is opened as long as the return button 174 is pressed or until the backrest has returned entirely to its full upright position. Since the return passage system including the passages 204 and 205 is freely open to the sump 153, free equalization of hydraulic fluid within the telescopic chair actuating column and more particularly within the manifold tube 2% and the telescopic tube 261 occurs during raising and lowering movements of the chair.

In order to relieve any leakage past the piston on the static side thereof, .a bleed line duct 2G7 connects the static end of the cylinder 17-1 with the return line duct 19 5 which, as pointed out previously is in free communication with the sump 1 53.

If independent operation 'of the backrest 21 and the leg and footrest 22 is desired, duplicate hydraulic cylinders and solenoid valves can be provided, both sets operating through the same supply and return ducts 179 and 195.

the convenient operative mounting thereof on the base.

, seat comparable to conventional barber chairs.

. l2 block 28 in communication with the respective manifolds 1'54 and 164 is shown.

From the foregoing, it will be apparent that there has been provided by the present invention an eflicient, rugged, and for the Work to be accomplished relatively simple elevatable seat operating device utilizing electrically powered hydraulic means with push button control. The system provides for a minimum height of the chair On the other hand, it affords a lift potential comparable to the best prior devices. Further, an electro-hydraulic recline mechanism is provided neatly integrated with the other operating mechanisms and circuits. Withal, unlimited rotation of the chair is permitted although in any desired swivelled position firm brake-held retention is afforded by the push button controlled brake mechanism.

Reference is made to our copending application Serial No. 135,062 filed August 30, 196 1 for certain disclosure and claims relating to the electrical control mechanism with respect to which certain improvements have been disclosed herein. 7

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

We claim as our invention:

1. In an actuator mechanism for an elevatable chair including a base structure and a chair seat frame structure,

an upwardly projecting manifold tube structure adapted to be fixedly mounted on the base structure,

a cylinder having an upper closed end and telescopically engaged with said manifold tube structure and defining with the manifold tube structure a pressure chamber,

said cylinder having a plurality of circumferentially spaced vertical cylinder bores spaced from said chamber and communicating with said chamber at their lower ends,

pistons in said bores having piston rods projecting above said cylinder and adapted to be supportingly attached to said chair frame structure,

said manifold tube structure having hydraulic fluid passage therein communicating adjacent to the upper end of the manifold tube structure with said cylinder chamber,

and means for delivering hydraulic fluid into said mani- I said base structure having fixedly thereon an upwardly projecting manifold tube structure,

a cylinder'having anupper closed end and telescopically engaged with said manifold tube structure and defining with the manifold tube structure a pressure chamber,

said cylinder having a plurality of circumferentially spaced vertical cylinder bores spaced from said" chamber and communicating with said chamber at their lower ends, A pistons in said bores havingpiston rods projecting abovesaid cylinder and supportingly attached to' said chair frame structure,- j said manifold tube structure having hydraulic fluid passage therein communicating adjacent to the upper end of the manifold tube structurewith said cylinder 7 chamber,

means for delivering hydraulic fluid into said manifold tube passage and thereby into said chamber and said bores for simultaneously elevating said'cylinder and said pistons and thereby eifecting compound elevation of said chair frame structure relative to said base structure, ,7 I and means including passages through said manifold structure and said cylinder and said seat frame structure for operating said backrest actuating hydraulic including a base structureand a chair seat frame structure, v an upwardly projecting manifold tube structure adapted to be fixedly mounted on the base structure,

a cylinderhavingan upper closed end and telescopically engaged with said manifold tube structure and defining with the manifold tube structure a pressure chamber,

said cylinder .having .a plurality of circumferentially spaced vertical cylinder bores spaced from said chamber and communicating with said chamber at their lowerrends, t V

pistons-in'tsaid boreshaving piston rods projecting above said cylinder .andaadapted to be supportingly attached to said chair frame structure, 1 I

said manifold tubestructure having hydraulic fluid passage therein communicating adjacent to the upper end of the manifoldtube structure with said cylinder chamber, r

means for delivering hydraulic fluid into said manifold tube'passage and thereby-into said chamber and said bores for simultaneously elevating said cylinder and said pistons and thereby eifectingrcompound elevation of said chair frame structure relative to said base structure,

said cylinder being rotatable relative to'said manifold tube structure,

brake means mounted in stationary relation to said base structure, I I and rotation lock means carried by said seat frame structure and coacting with said brake means to maintain the chair in selected rotary positions.

In combination in a chair elevating mechanism, base structure, chair frame structure, compound cylinder and piston vertical actuating mechanism connected at the lower end to said base structure and at the upper end to said chair frame structure andoperable to raise and lower the chair frame structure, said cylinder structure beingrotatable relative to the base structure, p and rotation lock means for maintaining the cylinder structure and chair frame structure in selected rotary positions relative to thebase structure including: 7 r

an angular cross-section torque tube depending fixedly from said frame structure about said cylinder structure, I r u a relatively telescopically mounted cylindrical tube about said torque tubeand havingcorotational bearing engagement with the torque tube,

a stationary brake housing disposed about and r having bearing means telescopically supporting a said cylindrical tube, u u and releasable brake means carried by said brake housing and engageable with said cylindrical tube to'maintain it and thereby said torque tube fa compound" cylinder," and; piston vertical actuating mechanism connected atathelowerend to said base structure and at the upper end to said chair frame structure and operable to raise and-lower the chair frame structure,

said cylinder structure being rotatable relative to the base structure,

and rotation ,lockmeans .for maintaining the cylinder Structure andchair frame structure in selected rotary positions relative to the base structure including:

an angular cross-section torque tube depending ffixedly from saidframe structure about said cylinder structure,

a relatively telescopically mounted cylindrical tube about said torque tube and having corotational bearing engagement-with the torque tube,

a stationary brake housing disposed about and having bearing means telescopically supporting said cylindrical tube,

brake band means carried by said brake housing 5 and engageable with saidtcylindrical tube,

.and means carriedby the brake housing and operable to actuate the brake band to hold said cylindrical tube against rotation but releasable to permit rotation of the cylindrical tube.

6,. ,In combination in a chair elevating mechanism,

a base structure, 7

a chair frame structure,

a compound cylinder and piston vertical actuating 'mechanism connected at the lower ,end to said base structure and at the upper end to'said chair frame structureand operable to raise and lower the chair ,frame structure,

said" cylinder structure'being rotatable relative to the base structure, a

and rotation lock, means for maintaining the cylinder structure and chair frame structure in selected rotary positions relative to the base structure including:

an angular cross-section torque tube depending fixedly from said frame structure about said cylinder structure,

a relatively telescopically mounted cylindrical tube about'said torque tube and having corotational bearing engagement with the torque tube,

a stationary brake housing disposed about and having bearing means telescopically supporting said cylindrical tube,

a brake band carried by said brake housing about said cylindrical tube,

a toggle linkage carried by the brake housing and operable to set the brake and release the brake, and means for actuating said'toggle linkage.

7. In combination in a chair elevating mechanism, a base structure,

a chair frame structure, I a compound cylinder and piston vertical actuating mechanism connected at the lower end to said base structure and at the upper end to said chair frame I structure '-and operable to raise and lower the chair frame structure,

said cylinder structure being rotatable relative to the base structure,

and rotation lock means, for maintaining the cylinder structure and chair frame structure in selected rotary said cylindrical tube, I r V brake means carried by said brake" housing and engage able with saidcylindrical tube, v 1 and means for actuating said brake means including a stationary brake housingdisposed about and t, having bearing means telescopically supporting a brake setting spring normally operating to bias the brake actuating'means into brake setting relation,

, and a hydraulic actuator operable to actuate said brake actuating means in opposition to 7 said spring to release the brake. 8. In a rotatable chair elevating mechanism including a base and a chair frame,

telescopic means connected to and operative between said base and chair frame for raising and lowering a chair. supported by the frame, and rotation interlock means for retaining said chair frame and thereby the supported chair in selected rotatably assumed positions of the chair frame relative to the base and including:

a torque tube depending from said chair frame about said telescopic means and having a plurality of angular circumferential facesand being telescopically elevatable With said chair frame,

a cylindrical rotatable interlock tube about and of substantially larger inside diameter than said torque tube,

adjustable bearing structure carried by said cylin- 9. In an elevatable and rotatable chair construction including a base and a chair frame for supporting a chair having a tiltable backrest and legrest,

chair lifting means between said base and said chair frame, I

a torque tube carried by the chair frame and depending therefrom about said lifting means,

a brake housing about said torque tube and having a brake mechanism operable to lock the torque tube and thereby the chair against rotation selectively and releasably, p

and electro-hydraulic means for operating said lifting means and said backrest and footrest and said brake mechanism.

References Cited by the Examiner UNITED STATES PATENTS 762,086 6/04 Ritter 60-52 1,242,109 10/17 Koken 248-418 1,242,110 10/17 Koken 248-418 1,364,887 1/21 Koken 248-418 1,748,298 2/30 May 248-404 X 1,814,874 7/31 Weber Q 60-52 1,856,493 5/32 May 248-404 X 2,653,648 9/53 Marshall 297-347 2,672,917 3/54 Collura 297-327 2,735,477 2/56 Wurm. et al. '6052 2,884,047 4/59 Abbott 297-361 2,969,645 6/61 Keifer 60-52 3,028,933' 4/62 Mueller 188-77 FRANK L. ABBOTT, Primary Examiner.

B. SHERRY, CLAUDE A. LE ROY,

Examiners. 

2. IN AN ELEVATABLE CHAIR CONSTRUCTION INCLUDING A CHAIR SEAT AND A BACKREST WHICH IS MOVABLE BETWEEN AN UPRIGHT IN A RECLINING POSITION RELATIVE TO SAID SEAT, HYDRAULIC MEANS FOR ACTUATING SAID BACKREST BETWEEN SAID POSITIONS, A BASE STRUCTURE, A CHAIR SEAT FRAME STRUCTURE, SAID BASE STRUCTURE HAVING FIXEDLY THEREON AN UPWARDLY PROJECTING MANIFOLD TUBE STRUCTURE, A CYLINDER HAVING AN UPPER CLOSED END AND TELESCOPICALLY ENGAGED WITH SAID MANIFOLD TUBE STRUCTURE AND DEFINING WITH THE MANIFOLD TUBE STRUCTURE A PRESSURE CHAMBER, SAID CYLINDER HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED VERTICAL CYLINDER BORES SPACED FROM SAID CHAMBER AND COMMUNICATING WITH SAID CHAMBER AT THEIR LOWER ENDS, PISTONS IN SAID BORES HAVING PISTON RODS PROJECTING ABOVE SAID CYLINDER AND SUPPORTINGLY ATTACHED TO SAID CHAIR FRAME, STRUCTURE, SAID MANIFOLD TUBE STRUCTURE HAVING HYDRAULIC FLUID PASSAGE THEREIN COMMUNICATING ADJACENT TO THE UPPER END OF THE MANIFOLD TUBE STRUCTURE WITH SAID CYLINDER CHAMBER, MEANS FOR DELIVERING HYDRAULIC FLUID INTO SAID MANIFOLD TUBE PASSAGE AND THEREBY INTO SAID CHAMBER AND SAID BORES FOR SIMULTANEOUSLY ELEVATING SAID CYLINDER AND SAID PISTONS AND THEREBY EFFECTING COMPOUND ELEVATION OF SAID CHAIR FRAME STRUCTURE RELATIVE TO SAID BASE STRUCTURE, AND MEANS INCLUDING PASSAGE THROUGH SAID MANIFOLD STRUCTURE AND SAID CYLINDER AND SAID SEAT FRAME STRUCTURE FOR OPERATING SAID BACKREST ACTUATING HYDRAULIC MEANS. 